I didn't intend to imply that matching forward/reverse DNS was a security measure I'd trust by itself, but it certainly doesn't hurt to implement as a "outer perimeter" measure in conjunction with IP-based rules and secure authentication... -C On Mon, May 14, 2001 at 10:24:54AM -0700, Adam McKenna wrote:
On Mon, May 14, 2001 at 11:46:05AM -0400, Christopher A. Woodfield wrote:
Reverse DNS by itself is insufficient for authentication, but enforcing matching forward and reverse DNS entries is much more reliable (no substitute for secret-based or cert-based authentication, but a good "front door" for something like tcp wrappers). at last check, tcpd and sshd can both be configured to block connections without matching forward/reverse records.
No. This is joke security, as is any security that relies on hostnames. TCP wrappers is basically worthless as a security measure unless you are using IP-based rules. And even then, it's deprecated in favor of kernel firewalling (In Linux) or ipfilter (on BSD's and other platforms that support it).
--Adam
-- --------------------------- Christopher A. Woodfield rekoil@semihuman.com PGP Public Key: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xB887618B